10732: ABC135 - B - 0 or 1 Swap
[Creator : ]
Description
We have a sequence $p$ = {$p_1,\ p_2,\ ...,\ p_N$} which is a permutation of {$1,\ 2,\ ...,\ N$}.
You can perform the following operation at most once: choose integers $i$ and $j$ $(1 \leq i < j \leq N)$, and swap $p_i$ and $p_j$. Note that you can also choose not to perform it.
Print `YES` if you can sort $p$ in ascending order in this way, and `NO` otherwise.
You can perform the following operation at most once: choose integers $i$ and $j$ $(1 \leq i < j \leq N)$, and swap $p_i$ and $p_j$. Note that you can also choose not to perform it.
Print `YES` if you can sort $p$ in ascending order in this way, and `NO` otherwise.
Input
Input is given from Standard Input in the following format:
```
$N$
$p_1$ $p_2$ $...$ $p_N$
```
```
$N$
$p_1$ $p_2$ $...$ $p_N$
```
Output
Print `YES` if you can sort $p$ in ascending order in the way stated in the problem statement, and `NO` otherwise.
Constraints
- All values in input are integers.
- $2 \leq N \leq 50$
- $p$ is a permutation of {$1,\ 2,\ ...,\ N$}.
- $2 \leq N \leq 50$
- $p$ is a permutation of {$1,\ 2,\ ...,\ N$}.
Sample 1 Input
5
5 2 3 4 1
Sample 1 Output
YES
You can sort $p$ in ascending order by swapping $p_1$ and $p_5$.
Sample 2 Input
5
2 4 3 5 1
Sample 2 Output
NO
In this case, swapping any two elements does not sort $p$ in ascending order.
Sample 3 Input
7
1 2 3 4 5 6 7
Sample 3 Output
YES
$p$ is already sorted in ascending order, so no operation is needed.